Polycystic ovary syndrome is the most common female endocrinopathy affecting the reproductive age group . It is a heterogeneous disorder. To analyse various clinical presentation of PCOS in population in North Chennai.To establish the role of  hormonal assay in diagnosing PCOS. To understand the correlation between clinical and endocrine changes with PCOS. Criteria: oligomenorrhea / anovulation ,lab. Findings/clinical findings suggestive of hyper androgenism. Direct inspection of poly cystic ovaries by ultrasound. Other etiologies for hyper androgenism ruled out. This study was carried from December 2015 to December 2016 in Stanley medical college hospital.50 patients were studies in age groups between 18–35 years. Written informed consent were obtained. Phenotype​ A is the most common presenting type of PCOS. Menstrual irregularities​is most presenting symptom in PCOS..There was no correlation between serum prolactin and PCOs.TVS is the most the important diagnostic tool. Obesity and overweight is  a most important modifiable  risk factor which will prevent this disorder.